Manufacture and treatment of threads of artificial filaments



June 13, 1939. J. B. DOVE 2,162,575

MANUFACTURE AND TREATMENT OF THREADS OF ARTIFICIAL FILAMENTS Filed Aug.12, 19:56 2 Sheets-Sheet 1 40/002076: Va/ras Pin :11 MW,

June 13, 1939. J, a DOVE 2,162,575

MANUFACTURE AND TREATMENT OF THREADS OF ARTIFICIAL FILAMENTS Filed Aug.12, 1936 2 Sheets-Sheet 2 efafin .B. 3076,

Patented June 13, 1939 UNITED STATES PATENT OFFICE MANUFACTURE ANDTREATMENT OF THREADS OF ARTIFICIAL FILAMENTS Application August 12,1936, Serial No. 95,639

14 Claims.

This invention relates to the manufacture of filaments, threads, films,or the like, by the extrusion of solutions through spinning jets orother extrusion orifices, Whether threads, films, or the like are formedby the wet coagulative or dry evaporative methods, and more specificallyit is directed to a process and. apparatus to be used in conjunctionwith the subject matter of my pending application entitled Rayonspinning machine, Serial No. 91,197, filed July 17, 1936, wherebyhomogeneous products of any desired denier and of unvarying uniformityare produced at less cost from a variety of raw materials such as pine,spruce, cotton linters, and the like, and at a greater spinning ratethan heretofore attainable.

One of the fundamental objects of this invention is to remove thelimitations heretofore attached to the spinning of low denier filamentsand to their drawing rate by thermo-mechanically determining thephysical and optical characteristics of the filaments, threads, or thelike such as tensile strength, contour, denier and homogeneity as thespinning solution passes through the. spinneret, stabilizing thesecharacteristics at the extrusion orifices by oil immersion of theextruding filaments under predetermined temperature conditions and thenmaintaining the product as thus fixed by temperature control throughoutthe remaining portion of the process.

Another object of this invention is to provide a method of the characterdescribed wherein by varying the temperatures within a pair oftemperature chambers jointly encasing a spinneret of the capillary tubetype and whichis highly responsive to temperature variations, theviscoidal character of the spinning solution maybe simultaneouslyaltered with the change in dimensions of the capillary tubes and theiroutlet orifices, brought about by the expansion and contraction of thespinneret, thus automatically effecting an adjustment between the rateof flow of the spinning solution and the size of the capillary tubes andtheir extrusion orifices, in accordance with the size of the filamentsrequired.

When the temperature of the viscose solution being spun is elevatedabove the normal for maximum spinning conditions there is a tendency fora reduction in viscosity to the extent that the surface tension of thejet solution becomes such a predominating factor that the spinningsolution leaves the jet orifices in a fluctuating or discontinuousinstead of a continuous and uniform stream resulting in unevenness ofthread. It is therefore one of the objects of this invention to overcomethis defect by extruding into a cold oil bath whereby surface tension ofthe filaments in the immediate vicinity of the extrusion orifices willbe materially lowered.

Another object of this invention is to provide such filaments,

method and apparatus whereby the filaments, threads or the like afterleaving the oil immersion bath are conducted, permeated and encased in afilm of oil to the coagulation bath under tempera- .ture and airexcluding conditions which gradually and uniformly bring thetemperature; of the filament to that of the coagulation bath withoutexposure to deteriorating atmospheric influences and the detrimentaleffects which have been observed when a temperature differential existsbetween the coagulation bath and that of the entering filaments.

Another object of this invention is to provide a comparativelyinexpensive apparatus which may be utilized substantially without changeto produce high grade products by either the dry evaporative or wetcoagulative method, and to effect a method and apparatus which willenable the production of artificial filaments, threads, films, or thelike of any size and at any spinning speed desired.

With these and other objects in view, which will become apparent as thedescription proceeds, the invention resides in the construction,combination and arrangement of parts, hereinafter more fully describedand claimed, and illustrated in the accompanying drawings, in which likecharacters of reference indicate like parts throughout the severalfigures, of which:

Fig. 1 is a side elevation of the spinning cell and tanks.

Fig. 2 is a longitudinal sectional view of the spinning cell.

Fig. 3 is a cross section on line 33 of Fig. 2.

Fig. 4 is a longitudinal section through the spinneret.

Fig. 5 is a face view of spinneret looking towards the right, in Fig.4,with the coupling removed.

Fig. 6 is a side View of the spinneret with the coupling removed.

Fig. 7 is a fragmentary longtiudinal sectional view similar to Fig. 2,showing the altered direction of the thread for dry spinning.

The instant invention briefly stated consists in directing a suitablyprepared spinning solution under the required pressure conditions intoand through the capillary tubes of a spinneret, the construction andmaterial of which is such as to render it highly responsive totemperature changes, the spinneret being housed. within and locatedbetween a pair of adjoining hot and cold temperature chambers, with theend containing the outlet orifices of the capillary device disposedbelow the level of an oil immersion bath within the cold chamber and itsremaining portion lying in the hot temperature chamber, this arrangementpermitting control of the size of the capillary tubes and their outletorifices by expansion and contraction of the spinneret; directing theextrusion products as they are spun by the spinneret into and upwardlythrough the oil immersion bath, then altering the course of thefilaments as they leave the bath and conducting them along adownwardlyinclined path; this reversal releasing the oil entrappedvapors and facilitatirig the draw or the filaments upwardly through theoil bath; then directing the filaments from the point of reversal to thecoagulation bath under temperature controlled and air excludingconditions, and finally directing the filaments into and upwardlythrough the coagulation bath at the temperature of the latter.

Investigators have been constantly striving to remove the limitationsimposed by existing methods on the spinneret, spinning rate of thefilaments and their fineness, without in so doing sacrificing thequality of the products formed with respect to uniformity, tensilestrength and homogeneity. To this end some have directed their attentionto the coagulation bath, while others have sought a solution of theproblem in the construction of the spinneret and by thermally treatingthe spinning solution before it reaches the spinneret, as it passestherethrough, and as it leaves the extrusion orifices. Although theseindividuals have unquestionably advanced the state of the art thecourses thus far taken appear to have limits beyond which it isimpossible to go without seriously impairing the resulting products.

The establishment of these facts gave rise to the assumption that thekey to the solution of the problem of increased output withoutconsequent deterioration of the product was to be found in the field ofmechanical rather than chemical research. Accordingly, the problem wasattacked from this angle, and after a systematic study extending over aconsiderable period the discovery was made that under the predeterminedpressure conditions a constant rate of flow could be obtained at thespinning orifices of the spinneret without regard to the size of theextrusion orifices if the latter were caused to expand and contract inaccordance with the size of the filaments desired, and if at the sametime the resistance to change of shape of the spinning solution werethermally adjusted to meet the changed dimensions of the spinningorifices. It was also found that by extruding the elemental filaments inan oil immersion bath under lowered temperature conditions, filamentsthat ordinarily would disintegrate under their own weight could be boundby the oil and readily delivered to the coagulation bath. It was furtherobserved that the particles of the filaments extruding from theextrusion orifices into the chilled oil were firmly bound internally andexternally due to the permeating and incasing action of the oil and thatthis association of particles formed at the extrusion orifices couldunder temperature controlled and atmosphere excluding conditions bemaintained throughout the remaining steps of the process. Thesediscoveries when combined in the apparatus forming the subject matter ofthe instant application produced a soft, velvety-like thread of unusualstrength (a six foot length sustaining a five pound weight), finenessand homogeneity at a spinning rate heretofore deemed impossible.

In the illustrated embodiment characterizing this invention there isshown a tank I adapted to contain a cellulose spinning solution 2suitably prepared for either the wet coagulative or dry evaporativeprocess. A comparatively small pressure tank 3 is connected to tank I bya pipe 4 in which is mounted a check valve 5. Connected to tank 3 bypipe 5 is a spinning cell A divided into the thermo-control compartmentsB; C, and D, and mounted in pipe 6 adjacent said cell A is a rotary pump1 adapted to deliver the spinning solution under a predeterminedpressure to the spinning cell A, as will directly more fully appear.

Said cell A comprises a tubular body portion 8 having an end wall 9 forthe heating or temperature chamber B and a partition or end wall In forthe cooling chamber 0, and which ends may be threadedly or otherwiseconnected to said chamber 8 as desired. Welded or suitably attached tothe tubular member 8 substantially central of its length are a pair ofspaced plates or partition walls H and I2 constituting, respectively,the inner end walls of the chambers B and C. The space intermediate saidplates is filled with an insulating material such as asbestos I3 inorder to maintain the relative thermal conditions of the chambers.Surrounding chamber C is a suitably mounted water jacket l4 formed atits upper side adjacent one edge with a water or other cooling fluidinlet opening l5 and at its lower side and adjacent its opposite edgewith a discharge or outlet opening l6. Extending from inlet 15 to outletI6 is a suitably mounted spiral baffle l1 forming a passageway, so thatthe cooling fiuid entering opening l5 will travel completely around saidchamber before reaching the outlet l6 and thoroughly cooling or chillingchamber C, as and for a purpose directly appearing. Lead-in pipe I8 issuitably connected to opening l4 and a source of fluid supply (notshown) and the fluid flow is normally controlled by the automaticcontrol valve l9.

In order to heat chamber B, a lead-in pipe 20 connected to a suitablesteam supply or other heating medium and communicating with said chamberas at 2| is adapted to deliver the heating medium to said chamber formedat its lower side with exhaust outlet 22, the temperature in saidchamber being normally controlled by automatic valve 23.

A substantially cone-shaped casing 24, forming chamber D, is suitablyattached to one end of tubular member 8 as at 25 and terminates at itsfree end in exhaust hood 26 having a discharge outlet 21 for the air orother cooling fluid ada mitted to said chamber by pipe 28 suitablyconnecting with said chamber as at 29 and with a source of fluid supplynot shown. The flow of said air under pressure to chamber D iscontrolled by automatic valve 30 similar to valves l8 and 22, as will bewell understood, and at the same time the vapors formed in chamber C aredrawn through openings 3| in wall l0 and exhausted through outlet 26,with the air stream passing therefrom, during operation of the device.as will hereinafter more fully appear.

The pipe 6 from pump I extends through end 9 within chamber B and hasmounted on its free end a spinneret or filament forming die structure Ecomprising an internally bored connecting portion 32 internally threadedas at 33 to receive the end of pipe 6 and is formed at its opposite endwith a lateral flange 34. A filament forming die member 35 constructedfrom a metal highly sensitive to temperature changes is formed at oneend with a flange 36 and is adapted to seatingly engage the flange endof portion 32 in alignment therewith, and mounted on said die member isa nut 31 complementally formed to receive the flange 36. Mounted onmember 32 and embracing fiange 34 is a ring nut 38 threadedly engagingnut 37 to securely lock and maintain die member 35 in aligningengagement with member 32. Nut 38 seats against the end member or plateH and the die member 35 is adapted to extend through plates II and I2and the insulation it with its extrusion face flush with the surface ofsaid plate [2 for communication with chamber C. Said die member 35 isformed with a number of capillary tubes 39 extending therethrough inslightly converging direction from their enlarged inlet ends 40 to theirinner ends or extrusion orifices 4|. Spaced from said orifices is anannular series of countersunk openings 42, in staggered relation withrespect to said openings 4!, extending about two-thirds of the waythrough said member 35, and which latter member is also formed on itsexterior surface with a series of circumferentially spaced grooves #32substantially corresponding in length to the countersunk bores 42, andwhich construction effects expansion and contraction of die member 35under the temperature control of chambers B and C, and thereby renderingsaid die highly responsive to temperature changes, so that by itsexpansion and contraction the viscosity and denier of the filaments iscontrolled in accordance with the extrusion speed of the filaments fromsaid die and the size or denier of the desired thread.

Wall l which separates chambers C and D is formed with an opening 43 anda packing oil gland structure 43' above and offset with respect to die35 through which is adapted to extend a thread delivery and gravity pipe44 which projects through an opening in end 35 of the exhaust hood 26and through opening 43 into the coagulating bath tank 41 and terminatingin nipple t8, as and for a purpose directly more fully appearing.

The opposite end of pipe 44 extends within the combined oil and coolingchamber C, and its upper wall is cut away as at 49 and the lower wallbent downwardly to provide the hump or apex 58 and the downwardlyinclined surface 5| terminating at a point 52 spaced from plate i2 justbelow the edge of the spinneret or die member 35. Said chamber C isadapted to be filled with an oil 53, preferably a vegetable oil,although other oils such as mineral oil may be used under certainconditions. The level of said oil should preferably be maintained at apoint above the upper edge of spinneret 35 and below apex 50. Thisconstruction is extremely important in view of the fact that chamber 13has a temperature range of 70 F. to 109 F., and chamber C a tempera turerange of 32 F. to 45 F., and as the filaments 54 are converginglyextruded from the orifices M Within a pressure range of 1-400 pounds persquare inch, and although they are subjected to the cooling effect ofthat portion of the spinneret extending through the cooling plate l2,they are yet in a heated condition and as they are submerged in the oilbath, the oil surfaces of the filaments are congealed entrainingparticles of water and other substances, and being lighter than oil,said filaments tend to ascend to the top of the oil along the incline52to the apex 58, and not only are the individual filaments coated butthe thread 55 made up of said filaments is also coated and is directedby gravity from point 59 to the discharge nozzle 56 and into thecoagulating solution 51 from, whence the thread 55 they stripped ofexcess oil but as they pass over' this point fissures or weakenedsurface areas occur in the congealed coating thereby permitting theescape of the entrained vapors, heated particles of water, etc., causingthe coating to immediately directly engage the filament surfaces andbecome sealed, and as they descend the gravity stretch of pipe 44 theyare further subjected to temperature control chamber D which is designedto bring their temperature to that of the bath solution 5'! so that notemperature differential will occur as the thread passes into said bath,as will hereinafter more fully appear.

In the event it is desired to convert the instant apparatus to the dryevaporative process, this may be accomplished by directing the fibersupwardly through the oil and air in chamber C and thence through theopening 58 formed in the top of the tubular section or casing 8, asclearly shown in Fig. 7 of the drawings. It is evident of course thatwhen the dry process is not used this opening may be closed by asuitable plug. Also, a pipe 59 having a control valve 66 is suitablyconnected to tubular portion 8 in communication with temperature orevaporating chamber C, by which, in any well known manner, the volatilesolvents may be returned from said chamber to the recovery plant. Itwill thus be seen that by merely changing the temperature prevailing inchamber C for the wet coagulative process, to that essential to the dryevaporative process, a change over from one process to the other may beaccomplished without any material structural changes.

With further reference to pipe 44, it will be noted that this pipe ispreferably constructed from hard rubber, which has been found especiallyefficacious, possibly owing to its acid and alkali resistant properties.In connection with the spinneret it is to be understood that thefilament forming spinneret or die 35 is readily interchangeable to varythe number offilament orifices and according to the type of threaddesired.

While it is thought that the operation of the invention would seem to beclear from the above description, it might be well to further state thatwhen a properly prepared spinning solution is contained in tanks I and3, the operation of pump 1 is controlled to deliver the solution to thespinneret within the spinning cell A at the desired pressure and thetemperatures in chambers B, C, and D are maintained relatively constantby suitable valves referred to as automatic. Variations in theoperations of these valves and according to predetermined operatingrequirements, controls the filament forming speed, viscosity, and sizeor denier of the thread desired. This is readily accomplished by thetemperature control, causing expansion and contraction of the capiL-lary tubes and extrusion orifices of the spinneret which latter ishighly sensitive to temperature variations.

Further, as the filaments are about to emerge and as they emerge fromthe extrusion orifices their surface tension is materially lowered, thuspreventing their disruption before reaching the oil bath, but no matterhow fine such elemental filaments may be, and without regard to the lowviscosity of the spinning solution required for very low denierfilaments, they will not disintegrate at the extrusion orifices, asheretofore has been their tendency. Immediately the filaments areextruded from said orifices they are subjected to a cold oil bath, andthis immersion in the oil fixes the association of their particles asdetermined by the spinneret or die both internally and externally and atthe same time further lowers their surface tension.

The said immersion effects the permeation and coating of the filamentswith oil and which causes vaporous particles to be entrained therein,and'as the filaments are directed out of the bath and up the inclinedsurface 5|, and as they pass over the hump 50 the outer congealedsurface of the oil coating tends to crack or weaken sufiiciently topermit the escape of said entrained vapors. This causes the coating toseal the opening and adhere directly to the surfaces of the filamentsand effect their bonding together as a thread, and which aids theirgavitational travel to the discharge nozzle, since the greater length ofpipe 44 from the apex 50 tends to overcome ascent of the inclinedsurface 5|, thereby effecting take-off of the filaments from thespinneret irrespective of their extrusion speed and preventing rufiingor fluifing of the fiber particles upon their extrusive contact with theoil, as otherwise would be their tendency. Also, according to thetemperature control in chamber D above mentioned, by the time they reachdischarge nozzle 56 they are of the same temperature as the coagulatingsolution 51.

The said oil treatment also produces a lubricating effect, in that, itaids the precipitating action of the coagulation bathwvithout alteringthe physical characteristics of the thread imparted to it at theextrusion orifices of the spinneret, and thereby imparts to the threadan extremely velvety texture while augmenting its tensile strength. Itwill further be apparent that the spinneret in forming the filaments,and their treatment during the remaining process, jointly contribute toproduce a thread of predetermined and nonvariable denier and of unusualstrength, irrespective of the extrusion speed of the filaments, andwhich denier owing to the particular sensitiveness of the spinneret andthe thermal control above described, may be instantly changed as desiredwithout disturbing the thread output rate.

With further reference to the oil contained in chamber B, it is to beunderstood that under certain operating conditions and in connectionwith certain types of thread. that other fluids or solu tions may beadded to the oil or substituted for the latter, as desired.

From the above it will be apparent that I have designed an apparatus forthe production of filaments, threads, films and the like by theextrusion of solutions thru spinning jets or other extrusion orifices bythe wet coagulative or dry evaporative methods of unusual texture andstrength irrespective of the extrusion speed and so thermo-mechanicallycontrolled that the denier may be varied without interruption of thethread output, comprising few parts, simple in construction, versatilein adaptive use, manufacturable at a minimum cost, and efficient for thepurposes intended.

Although in practice I have found that the form of my inventionillustrated in the accompanying drawings and referred to in the abovedescription as the preferred embodiment is the most efiicient andpractical; yet realizing the conditions concurrent with the adoption ofmy invention will necessarily vary, I desire to emphasize that variousminor changes in details of construction, proportion and arrangement ofparts, may be resorted to within the scope of the appended claimswithout departing from or sacrificing any of the principles of thisinvention.

Having thus described my invention, what I desire protected by LettersPatent is as set forth in the following claims:

1. An apparatus for spinning textile filaments from a spinning solutionincluding a spinning cell, a spinneret within the cell, the latterincluding a plurality of extrusion orifices, thermomechanical means inconnection with the cell and spinneret for producing filaments ofpredetermined sizes and shape, said thermo-mechanical means comprising aheating chamber, a cold chamber adapted to contain a fluid such as oil,said spinneret being mounted between said chambers with its extrusionorifices opening into the cold chamber, a controlled refrigerating meansin connection with said cold chamber, whereby the filaments aresubjected to an oil immersion bath and expansion and contraction of theextrusion orifices is selectively effected by temperature control of thehot and cold chambers, means for directing the filaments through saidbath, and means for conducting the spun and oil treated filaments to theexterior of the cell under temperature controlled and atmosphereexcluding conditions.

2. An apparatus for spinning artificial filaments, comprising a spinningcell, a spinneret within the cell, and including a series of extrusionorifices, means for directing a spinning solution to and through theextrusion orifices to produce filaments, means formed on the spinneretto increase its response to temperature changes, said means including anannular series of external grooves, means coacting with the spinneretfor effecting its expansion and contraction to change the size of itsextrusion orifices, said means comprising a heating chamber, a coldchamber insulated from said heating chamber, and a refrigerating meansin connection with said cold chamber and means for conducting thefilaments from the spinneret to the exterior of the cell undertemperature controlled and atmosphere excluding conditions.

3. An apparatus for spinning a textile filament from a spinning solutionincluding hot and cold chambers and a temperature chamber, a spimieretresponsive to temperature changes mounted in said hot and cold chambersand having a filament extrusion orifice communicating with said coldchamber, filament conducting means extending within the cold chamber andthrough the temperature chamber for delivering the filamentstherethrough free from atmospheric conditions.

4. An apparatus for spinning textile filaments from a spinning solutionincluding a spinning cell, hot and cold chambers in said cell, aspinneret responsive to temperature changes mounted in said chambers andhaving filament extruding orifices communicating with the cold chamber,the latter adapted to contain a filament treating substance in intimatecontact with said orifices, a conduit having one end connected to thespinneret within the hot chamber and the other end with a source ofspinning solution exterior of said chamber, means for heating saidspinneret and conduit within said chamber, a refrigerating means inconnection with the cold chamber for controlling the temperature of saidsubstance whereby expansion and contraction of said orifices isselectively effected, means in connection with said cold chamber fordirecting the treated filaments from said chamber and to the exterior ofthe cell free from atmospheric influences, and temperature control meansfor said filament directing means.

5. An apparatus for spinning textile filaments from a spinning solutionincluding a spinning cell and a coagulating solution containing tank,hot and cold chambers in said cell, a spinneret responsive totemperature changes mounted in said chambers and having filamentextruding orifices communicating with the cold chamber, the latteradapted to contain a filament treating substance, means for conductingthe treated filaments from said chamber to said coagulating solutionfree from atmospheric influences, and temperature control means for saidfilament conducting means, whereby the temperatures of the filaments andthe coagulating solution are the same at the time the filaments enterthe solution.

6. A method for thermally varying the dimensions of the extrusionorifice of a spinneret consisting in subjecting the inlet end of thespinneret to the action of heat, intimately contacting the extrusion endof the spinneret with a fluid and regulating the temperature of saidfluid with a refrigerant to control the effect of said heat applicationupon the extrusion orifice.

7. A method of thermally varying the dimensions of the extrusion orificeof a spinneret consisting in subjecting the inlet end of the spinneretto the action of heat, intimately contacting the extrusion end of saidspinneret with a fiuid passing into the spinneret and around theextrusion orifice, and regulating the temperature of said fluid with asuitable refrigerant to control the effect of said heat application uponthe extrusion orifice.

8. A method of thermally varying the dimen sions of the extrusionorifice of a spinneret and simultaneously changing the viscosity of thespinning solution as it passes to and through said spinneret consistingin surrounding the inlet end of the spinneret with a heating zone,directing the spinning solution through said zone to the inlet end ofsaid spinneret, regulating the temperature of said heating zone inaccordance with the degree of heat to be applied to the spinningsolution and to the inlet end of the spinneret, intimately contactingthe extrusion end of the spinneret with a fluid, and regulating thetemperature of said fluid with a circulating refrigerant to control theeffect of the action of heat upon the inlet end of said spinneret.

9. A method for thermally varying the dimensions of the extrusionorifices of a spinneret and simultaneously changing the viscosity of thespinning solution as it passes to and through saidspinneret consistingin surrounding the inlet end of the spinneret with a heating zone,directing the spinning solution through said zone to the inlet end ofsaid spinneret, regulating the temperature of said heating zone inaccordance with the degree of heat to be applied to the spinningsolution and to the inlet end of the spinneret, intimately contactingthe extrusion end of said spinneret with a fluid passing into thespinneret and around the extrusion orifices and regulating thetemperature of said fluid with a circulating refrigerant to control theeffect of the action of heat upon the inlet end of said spinneret.

10. An apparatus for spinning textile filaments from a spinning solutionincluding a spinneret having an extrusion orifice, thermo-mechanicalmeans in connection with the spinneret for producing filaments ofdifferent sizes, said thermomechanical means comprising a heatingchamber and a cold chamber insulated from said heating chamber andadapted to contain a fluid, said spinneret having its inlet end in theheating chamber and its extrusion orifice in said cold chamber, acontrolled refrigerating means in connection with the cold chamber,whereby the size of said extrusion orifice may be varied, and

means for delivering the filament from said cold chamber.

11. An apparatus for spinning textile filaments from a spinning solutionincluding a spinneret having a plurality of extrusion orifices,thermomechanical means in connection with the spinneret for producingfilaments of diiferent sizes, said thermo-mechanical means comprising aheating chamber, a cold chamber insulated from said heating chamber andadapted to contain a cooling fluid, said spinneret being mounted betweensaid chambers with its extrusion orifices in said cold chamber, arefrigerating means in connection with the cold chamber, whereby thesize of the extrusion orifices may be varied, said filaments beingsubjected as they are extruded to an immersion bath in said coolingfluid, and means for directing the filaments out of said bath and fromsaid cold chamber.

12. An apparatus for spinning a textile filament from a spinningsolution including hot and cold chambers insulating materialintermediate said chambers, a spinneret responsive to temperaturechanges mounted in said hot and cold chambers and having a filamentextrusion orifice communicating with said cold chamber, said coldchamber adapted to contain a cooling fluid in intimate contact with saidorifice, and a controlled refrigerating means in connection with saidcold chamber, whereby the size of said orifice may be varied, and meansfor delivering the filament from said cold chamber.

13. An apparatus for spinning textile filaments from a spinning solutionincluding hot and cold chambers insulated from each other, said coldchamber adapted to contain a cooling fluid, a spinneret responsive totemperature changes mounted in said hot and cold chambers and havingfilament extrusion orifices communicating with said cold chamber,additional means formed in said spinneret permitting the fluid to passinto the spinneret and around the extrusion oriflces, refrigeratingmeans in connection with the cold chamber controlling the temperature ofsaid fluid whereby the dimensions of said orifices are selectivelyvaried, and means for delivering the filaments from said cold chamber.

. 14. An apparatus for spinning textile filaments from a spinningsolution including hot and cold chambers insulated from each other, saidcold chamber adapted to contain a fluid, a spinneret responsive totemperature changes mounted in said hot and cold chambers and havingfilament extrusion orifices communicating with said cold chamber and inintimate contact with said fluid, means for relatively controlling thetemperatures in the respective chambers, whereby the dimensions of saidorifices are selectively varied, the temperature control of the heatingchamber adapted to simultaneously control the viscosity of the solutionpassing therethrough and through the spinneret, and means for deliveringthe filaments from said cold chamber.

JOHN B. DOVE.

